The researchers said their findings could be used to create a simple screening tool to identify people at higher risk for rheumatoid arthritis, an autoimmune disease that causes pain, swelling, stiffness and loss of function in the joints, and can also affect other body organs.

The team at the Arthritis Research U.K. Epidemiology Unit examined data from more than 25,000 people, aged 40 to 79, who were followed over a number of years. When they compared 184 people who developed rheumatoid arthritis with people who did not, the researchers found that smoking, obesity and diabetes all were linked to an increased risk.

The investigators also discovered that drinking small amounts of alcohol and being in a higher social class were associated with a reduced risk of developing the painful joint disease.

Women who had more than two children and breastfed for a shorter amount of time also were found to have a higher risk of developing rheumatoid arthritis, the study authors said.

"The factors we studied give us vital clues to the early events in the process that ends in someone developing rheumatoid arthritis. They are also simple to ask about and can be used as part of a prevention program," study leader Ian Bruce, a professor of rheumatology at the University of Manchester and a senior investigator with the National Institute for Health Research in the United Kingdom, said in a university news release.

The study was published in the March 17 issue of the journal Annals of the Rheumatic Diseases.

Although the study found an association between certain lifestyle factors and development of rheumatoid arthritis in the study population, it did not prove a cause-and-effect relationship.